Presentation on theme: "The Ocean Floor Chapter 14. What is Oceanography? Oceanography science that draws on the methods and knowledge of geology, chemistry, physics, and."— Presentation transcript:
What is Oceanography? Oceanography science that draws on the methods and knowledge of geology, chemistry, physics, and biology to study all aspects of the world ocean
Water on the Earth 61% found in the Northern Hemisphere 81% found in the Southern Hemisphere 71% total on Earth
The Four Oceans Pacific –largest and the greatest average depth Atlantic –shallowest Indian Arctic
Mapping the Ocean Floor Bathymetry measurement of ocean depths and the charting of the shape or topography of the ocean floor
Mapping the Ocean Floor Sonar is an acronym for sound navigation and ranging. It is also referred to as echo sounding transmitting sound waves toward the ocean bottom
Mapping the Ocean Floor Satellites able to measure small differences by bouncing microwaves off the ocean surface
Mapping the Ocean Floor Submersibles are small underwater crafts used for deep-sea research remotely operated vehicles (ROVs)
Main Ocean Floor Regions Continental Margin Ocean Basin Floor Mid-Ocean Ridge
Continental Margin Continental shelf is the gently sloping submerged surface extending from the shoreline mineral deposits, large reservoirs of oil and natural gas, and huge sand and gravel deposits Continental slope is the steep gradient that leads to the deep-ocean floor Continental rise is the gently sloping surface at the base of the continental slope.
Ocean Basin Floor Trenches form at the sites of plate convergence where one moving plate descends beneath another Abyssal plain is a very level area of the deep-ocean floor Seamount is an underwater volcano at least 1000 meters above the deep-ocean floor Guyot is an eroded, submerged seamount.
Mid-Ocean Ridges Seafloor spreading process by which plate tectonics produces new oceanic lithosphere at ocean ridges New ocean floor is formed Hydrothermal Vents mineral-rich water is heated by the hot, newly-formed oceanic crust and escapes through cracks in the oceanic crust into surrounding ocean water
Types of Seafloor Sediments Terrigenous sediments: mineral grains that were eroded Biogenous sediments: shells and skeletons of marine animals and algae Hydrogenous sediment: minerals that crystallize directly from ocean water through various chemical reactions
Resources From the Sea Oil and natural gas main energy products currently being obtained from the ocean floor Gas hydrates compact chemical structures made of water and natural gas
Resources From the Sea Sand and Gravel Used to fill in recreational beaches and make concrete Manganese nodules Extracted to make permanent magnets and engine parts Evaporative Salts halite—table salt Used for preserving foods and de-icing roads
Which Ocean Has the Greatest Salt Quantity? Dead Sea 38% salt content